Improvement in hardening steel



LEM w Q M M W NAM M.

0. MARLAND.

HARDBNING STEEL.

Patented June 8, 1869.

OBADIAHMARLAND, OF BOSTON, MASSACHUSETTS.

Letters Patent N 91,142, dated June 8, 1869.

IKPROYEMENT nr HARDEHING STEEL.

The Schedule referred to in these Letters Patent and making part of thename.

To all whom it may concern Be it known that I, Ossmm MARLAND, of Boston,in the county of Suffolk, and State of Massachusetts, have inventedImprovements in Hardening Steel; and I do hereby declare that thefollowing, taken in connect-ion with the drawings which accompany andform part of this specification, is a description of my inven,

tion, sufficient to enable those. skilled in the art to practise it.

My invention has reference to a process and apps. ratns designed by me,primarily, for hardening sheets of considerable-area and thickness, madeup of layers of iron. and steel combined, by welding, anddesigned forforming the walls of burglar-proof safes and vaults, or for employmentas defensive armor-plates for war vessels and fortifications, though myinvention is applicable to hardening various objects :of steel alone, orof steel and iron combined.

' Myinvention may be said to consist in subjecting the hot metal to behardened, to the action of a cold current, maintained under pressure,while it acts on the heated metal ny means of a head or force, checkedfrom. free delivery or outlet, so that the current will press againstthe heated metal, and will flow past it iapidly,'changiug quickly theheated atoms of the current for cold atoms, and thus rapidiy absorbingand carrying oif the caloric from the heated metal. The current employedwill generally and preferably be pure cold water, which may be suppliedfroma fall, head,

or reservoir, or by a pump, bntother liquids than water may be employed,or varioiis fluid mixtures.

may be, made use of, or substances soluble in water may be mixedtherewith,or' air, or gaseous, or vaporous currents may be. used.

My invention further consists in the uetails of construction andarrangement, and the equivalents therefor, described beyond, withreference to the drawings,

by which I practise my process of subjecting heated steel to the actionof a retarded or checked current of cold fluid, under pressure.

Figure 1 showsa sectional elevation of my improved apparatus, and

Figure 2, a sectional plan of the same, arranged and designed forhardening sheets or plates of steel, or sheets or plates of weldedlayers of steel and iron.

or represents the sides, bottom, and top of a trough, designed toreceive and hold vertically on its edge, the heated plate, b, the troughbeing given an inclination so that if the cooling-current is a liquid,it may drain freely from below the lower edge of'the plate, which restson a grid, or serlesof bars 0, located above the inner surface of thebottom of the trough.

In recesses in the sides of the trough are fitted two adjustablevertical plates d, arranged so that they can bemoved toward and from thetrough-centre, said plates being provided on their adjacent faces withpins or studs 0, which come into contact with the sides of the hot metalplate,.and keep the surfaces of the heated plate apart from the surfacesof the adjustable plates, so as to permit free flow of thecooling-current past the-heated metal.

The pins or studs 0 are longer where the coolingcnrrent enters and firststrikes against the heated plate, than they are at the other end of saidplate,

this giving'passageways which gradually contract and keep. the atomsforming the cooling-current pressed against the sides of the heatedplate, and increasing the velocity of the current as it progresses alongthe heated plate.

The top of .the trough is provided with a cover or door, g, which, whenopened allows the heated plate to be lowered into the trough till itrests on the bars 0, and then either or both the side plates at areadjusted by means of the screws f; or other more quickly-movingmechanical devices, till the ends of the studs 0, in

both plates :1, bear against the surfaces of the heated plate b.

The ends of the screws fare coupled to plates d, so as to retract saidplates readily, as well as press them toward each other.

In place of the screws, toggle-joints may be used to press the plates dtoward the heated plate, and to retract the plates d, and saidtoggle-joints may have their resisting pivots made movable, so as toadjust and adapt them to operate on any thickness of plate, saidresisting pivots being made by screws adjustable as to position.

Then thevcover g is closed over the plate 12, leaving room, however,between the inner surface of the cover and the top edge of the plate,for the passage of the cooling-current.

At the outletend of the trough is provided any suitable check or valve,It, made adjustable, so as to contract the delivery fromthe trough, toany desired extent.

If the coonng-current is to be a liquid, supplied from a cistern, or.reservoir, or head, then the inlet-end of the trough is provided with avalve or gate, a, which is to be turned or opened as soon as the plateI) is fixed in place, and the cover 9 closed and secured. Then theliquid fills the trough instantly, and flowing past the'plate b on allits surfaces, abstracts its heat very quickly, and hardens the plate,discharging the abstracted caloric with the current which escapes pastthe check h.

If the cooling-current is to be supplied by the action of a pump, fan;or bellows, then the valve or gate 1'. may be dispensed with,

The plate b, when large, is manipulated in placin itin and removing itfrom the trough by the aid 0 cranes, and other suitable appliances.

To keep the lower edge of plate b from lodging on the studs 0, as it islowered into the trough, suitahle temporary fenders are made to extenddown the plates at, between the studs 0, said fenders being withdrasmprevious to clamping the plate b between the stu s.

When cooling-liquids are supplied from a head or reservoir, any leakagewhich takes place past the valve or gate 5, will cause no trouble to theoperatives in placing and securing the hot plate b, as the liquid willflow freely oil under thesupporting-bars 0..-

Near the check-valve in the trough are located bars k, against which theend oi the heated plate abuts, which bars keep the plate from beingmoved along in the trough, toward the check-valve, by'the force of thecooling-current.

The studs between which the heated plates are clamped being ofequallengths, where opposed to-each other, said plates are subjected on eachside to the action of equal quantities of the cooling-current, and theresult is that the plates are hardened with very little-warping ortwisting.

I prefer in all cases to make use of the valve or gate g, as I donotbelieve that a pump or fan will act to deliver instantaneously asuiilcient volume of coolingcurrent to produce the best possibleresults.

With a head of water of about ten pounds pressure, and in suiiicientquantity, I have hardened large, thick plates of combined welded layersof iron and steel, to an extent which rendered futile all attempts todrill the plates with the hardest steel drills.

The water used need not be wasted, and may be collected as it flows pastthe heated plate, and may be used again and again, by being pumped backinto the elevated reservoir, which, if necessary, may be supplied withice.

I claim- 1. The process ior hardening steel, consisting in subjectingthe heated steel to the action of a cooling-current, which is maintainedunder pressure in a receptacle for the heated steel, through whichreceptaclethe ooling-current flows, by the action of a head or pressureagainst is contracted outlet, substantially as described.

2. Also, a receptacle for the heated steel article, arranged with aninlet and outlet for the cooling-current, when shaped to correspond tothe form of the piece to be hardened, and to permit a substantiallyuniform flow'of'the cooling-currentpast all the surfaces of said piece,substantially as described.

3. Also, a receptacle for the piece to be hardened, when provided withadjustable studs, arranged to clamp and hold said piece in position forthe action thereon of the cooling-current.

4. Also, a receptacle for the piece to be hardened, when provided withan inlet-valve or gate, and a gridor series of bars, 0, arranged toallow deposit or drainage of leakage of the cooling medium, and to admitthe contact of the cooling-current with the lower surtime of said piece.

5. Also, the combination of the check-bars 7a with the receptacle forthe heated steel, substantially as and for the purpose specified.

6. Also, the combination, with the receptacle for the hot steel, of acover or door, provided with means for looking it when closed,substantially as described.

7. Also, the combination, with the receptacle for the hot steel, ofadjustable plates, arranged to contract the area of the passage of thecooling-current, as it passes from the inlet to the outlet,substantially as and for the purpose specified.

OBADIAH MABLAND.

Witnesses:

J. B. Onosnr, FRANCIS Gocan.

